Christian Kandler - Academia.edu (original) (raw)
Papers by Christian Kandler
Personality Science, 2021
Personality traits continue to change throughout the lifespan. However, we still know little abou... more Personality traits continue to change throughout the lifespan. However, we still know little about when, why, and how personality traits change. In this paper, we review the current state of scientific evidence regarding the nature, sources, and processes of personality trait stability and change. We revisit past disputes over the relative importance of genetic and environmental influences, discuss studies on life events and personality trait development, and summarize theory and research on personality change processes. In doing so, we derive general principles of personality trait development, highlight limitations of past research, and present the broad outlines for future research on personality trait development, with a particular emphasis on relevant methodological issues and conceptual challenges.
Little research has examined age differences by using more than one source of information. We com... more Little research has examined age differences by using more than one source of information. We compared age differences in Five-Factor Model (FFM) facets and nuances in self-reports and ratings by knowledgeable informants using samples from three countries (Estonia, Germany, and the Czech Republic; N=5,624). We hypothesized that age differences would be larger in self- than informant-reports, because of greater social desirability in self-descriptions with advancing age. Indeed, we found that age differences were systematically smaller in informant-reports compared to self-reports; this trend was stronger for traits independently rated as socially desirable. As age differences may be best approximated by average trends of self- and informant-reports, we provide meta-analytic age trends for multi-rater composite scores of the FFM facets and nuances.
Current Directions in Psychological Science, 2020
There is now compelling evidence that people’s typical patterns of thinking, feeling, striving, a... more There is now compelling evidence that people’s typical patterns of thinking, feeling, striving, and behaving are both consistent and malleable. Therefore, researchers have begun to examine the distinct sources of personality stability and change. In this article, we discuss traditional classifications of sources, review key findings, and highlight limitations and open questions in research on personality stability and change. We conclude by describing an integrative model and by outlining important directions for future research.
Twin Research and Human Genetics, 2019
The Study of Personality Architecture and Dynamics (SPeADy) is a German research project that aim... more The Study of Personality Architecture and Dynamics (SPeADy) is a German research project that aims to investigate the sources of interindividual differences in intraindividual personality development. The main focus lies in the dynamic interplay between more stable core characteristics and more environmentally malleable surface characteristics, as well as between personality and life experiences over time. SPeADy includes a twin family study encompassing data from 1962 individuals (age: 14–94) of 682 families, including 570 complete twin pairs (plus 1 triplet set), 327 parents, 236 spouses and 145 children of twins. Data collection started in 2016 and data from the first wave are currently obtainable as open source. Available data comprise a broad range of personality variables, such as personality trait constructs, motives, interests, values, moral foundations, religiosity and self-related concepts. For the currently ongoing second wave of data collection, we added retrospective re...
Zeitschrift für Psychologie, 2019
This study was designed to provide detailed estimates of genetic and environmental sources of var... more This study was designed to provide detailed estimates of genetic and environmental sources of variance in the HEXACO personality traits. For this purpose, we analyzed data from a German extended twin family study including 573 pairs of twins as well as 208 mothers, 119 fathers, 228 spouses, and 143 offspring of twins. All participants provided self-reports on the HEXACO-60. Extended twin family analyses using structural equation modeling (SEM) yielded that additive and nonadditive genetic influences accounted for about 50% of the variance in personality traits. The remaining variance was primarily due to individual-specific environmental sources and random measurement error. Spousal similarity in Openness was attributable to assortative mating, whereas spousal similarity in Honesty-Humility was attributable to environmental circumstances, partly due to a shared social background and spouse-specific effects. Our analyses yielded specifics for different personality traits. However, transmission of trait similarity from one generation to the next was primarily genetic.
Personality traits are powerful predictors of outcomes in the domains of education, work, relatio... more Personality traits are powerful predictors of outcomes in the domains of education, work, relationships, health, and well-being. The recognized importance of personality traits has raised questions about their policy relevance – that is, their potential to inform policy actions designed to improve human welfare. Traditionally, the use of personality traits in applied settings has been predicated on their ability to predict valued outcomes, typically under the assumption that traits are functionally unchanging. This assumption, however, is both untrue and a limiting factor on using personality traits more widely in applied settings. In this paper, we present the case that traits can serve both as relatively stable predictors of success and actionable targets for policy changes and interventions. Though trait change will likely prove a more difficult target than typical targets in applied interventions, it also may be a more fruitful one given the variety of life domains affected by p...
European Journal of Personality, 2019
In two studies, we examined the genetic and environmental sources of the unfolding of personality... more In two studies, we examined the genetic and environmental sources of the unfolding of personality trait differences from childhood to emerging adulthood. Using self–reports from over 3000 representative German twin pairs of three birth cohorts, we could replicate previous findings on the primary role of genetic sources accounting for the unfolding of inter–individual differences in personality traits and stabilizing trait differences during adolescence. More specifically, the genetic variance increased between early (ages 10–12 years) and late (ages 16–18 years) adolescence and stabilized between late adolescence and young adulthood (ages 21–25 years). This trend could be confirmed in a second three–wave longitudinal study of adolescents’ personality self–reports and parent ratings from about 1400 Norwegian twin families (average ages between 15 and 20 years). Moreover, the longitudinal study provided evidence for increasing genetic differences being primarily due to accumulation of...
European Journal of Personality, 2018
This study investigated the association between different experiences of parenting and individual... more This study investigated the association between different experiences of parenting and individual right–wing authoritarianism (RWA) using twin family data comprising self– and informant reports. We applied a design that allowed us to examine whether the link between retrospective assessments of parenting and current RWA is effectively environmental or whether the association is attributable to genetic influences. We hypothesized that an authoritarian parenting style (low responsiveness and high demandingness) provided by the parents is associated with higher offspring's RWA, and that this association is similar for both twin siblings as a function of their genetic relatedness and shared familial experiences—that is, genotype–environment correlation. A sample of 875 twins as well as 319 mothers and 268 fathers completed a questionnaire on twins’ parental environment and their own authoritarian attitudes. Additionally, 1322 well–informed peers assessed twins’ RWA. Applying structu...
We adopted an expert-rating approach to generate a consensus Five Factor Model (FFM) profile of t... more We adopted an expert-rating approach to generate a consensus Five Factor Model (FFM) profile of the psychologically healthy person. In addition, we collected ratings from scholars with expertise in positive psychology and two samples of undergraduate psychology students to examine the agreement within and between different groups of raters. We then examined the reliability, heritability, rank-order stability, external validity, and normativeness of this expert-generated FFM profile of the healthy personality using data from seven different samples (N > 3,000). To do this, we computed a healthy FFM score for each participant by using intraclass q-correlation to match individual FFM profiles to the healthy personality prototype. Through these analyses, we aim to provide an initial but nonetheless comprehensive description of the nature and correlates of the healthy personality from a contemporary basic trait perspective.
Journal of Personality and Social Psychology, 2017
It has been argued that facets do not represent the bottom of the personality hierarchy-even more... more It has been argued that facets do not represent the bottom of the personality hierarchy-even more specific personality characteristics, nuances, could be useful for describing and understanding individuals and their differences. Combining two samples of German twins, we assessed the consensual validity (correlations across different observers), rank-order stability, and heritability of nuances. Personality nuances were operationalized as the 240 items of the Revised NEO Personality Inventory (NEO-PI-R). Their attributes were examined by analyzing item residuals, controlling for the variance of the facet the item had been assigned to and all other facets. Most nuances demonstrated significant (p < .0002) cross-method agreement and rank-order stability. A substantial proportion of them (48% in self-reports, 20% in informant ratings, and 50% in combined ratings) demonstrated a significant (p < .0002) component of additive genetic variance, whereas evidence for environmental influences shared by twins was modest. Applying a procedure to estimate stability and heritability of true scores of item residuals yielded estimates comparable to those of higher-order personality traits, with median estimates of rank-order stability and heritability being .77 and .52, respectively. Few nuances demonstrated robust associations with age and gender, but many showed incremental, conceptually meaningful, and replicable (across methods and/or samples) predictive validity for a range of interest domains and body mass index. We argue that these narrow personality characteristics constitute a valid level of the personality hierarchy. They may be especially useful for providing a deep and contextualized description of the individual, but also for the prediction of specific outcomes.
Journal of personality and social psychology, Jan 21, 2016
This multitrait multimethod twin study examined the structure and sources of individual differenc... more This multitrait multimethod twin study examined the structure and sources of individual differences in creativity. According to different theoretical and metrological perspectives, as well as suggestions based on previous research, we expected 2 aspects of individual differences, which can be described as perceived creativity and creative test performance. We hypothesized that perceived creativity, reflecting typical creative thinking and behavior, should be linked to specific personality traits, whereas test creativity, reflecting maximum task-related creative performance, should show specific associations with cognitive abilities. Moreover, we tested whether genetic variance in intelligence and personality traits account for the genetic component of creativity. Multiple-rater and multimethod data (self- and peer reports, observer ratings, and test scores) from 2 German twin studies-the Bielefeld Longitudinal Study of Adult Twins and the German Observational Study of Adult Twins-we...
European Journal of Personality, 2014
Most theories of personality development posit that changes in life circumstances (e.g. due to ma... more Most theories of personality development posit that changes in life circumstances (e.g. due to major life events) can lead to changes in personality, but few studies have examined the exact time course of these changes. In this article, we argue that time needs to be considered explicitly in theories and empirical studies on personality development. We discuss six notions on the role of time in personality development. First, people can differ before the event. Second, change can be non–linear and discontinuous. Third, change can be reversible. Fourth, change can occur before the event. Fifth, control groups are needed to disentangle age–related and event–related changes. Sixth, we need to move beyond examining single major life events and study the effects of non–normative events, non–events, multiple events, and minor events on personality. We conclude by summarizing the methodological and theoretical implications of these notions. Copyright © 2014 European Association of Personal...
European Journal of Personality, 2014
Increasing numbers of empirical studies provide compelling evidence that personality traits chang... more Increasing numbers of empirical studies provide compelling evidence that personality traits change across the entire lifespan. What initiates this continuing personality development and how does this development proceed? In this paper, we compare six theoretical perspectives that offer testable predictions about why personality develops the way it does and identify limitations and potentials of these perspectives by reviewing how they hold up against the empirical evidence. While all of these perspectives have received some empirical support, there is only little direct evidence for propositions put forward by the five–factor theory of personality and the theory of genotype → environment effects. In contrast, the neo–socioanalytic theory appears to offer a comprehensive framework that fits the empirical findings and allows the integration of other, more specialized, perspectives that focus on specific aspects of personality development like the role of time, systematic differences b...
Journal of Personality, 2010
This study considered the validity of the personality structure based on the Five-Factor Model us... more This study considered the validity of the personality structure based on the Five-Factor Model using both self-and peer reports on twins' NEO-PI-R facets. Separating common from specific genetic variance in self-and peer reports, this study examined genetic substance of different trait levels and rater-specific perspectives relating to personality judgments. Data of 919 twin pairs were analyzed using a multiple-rater twin model to disentangle genetic and environmental effects on domain-level trait, facetspecific trait, and rater-specific variance. About two thirds of both the domain-level trait variance and the facet-specific trait variance was attributable to genetic factors. This suggests that the more personality is measured accurately, the better these measures reflect the genetic structure. Specific variance in self-and peer reports also showed modest to substantial genetic influence. This may indicate not only genetically influenced self-rater biases but also substance components specific for self-and peer raters' perspectives on traits actually measured. Few behavioral genetic studies have focused on personality traits measured with two or more indicators like facet scales (Jang, Livesley, Angleitner, Riemann, & Vernon, 2002) or multiple raters such as self-and peer judges (Riemann, Angleitner, & Strelau, 1997). No study has combined the advantages of both so far, although a
European Journal of Personality, 2010
We describe a behavioural genetic extension of the classic multitrait‐multimethod study design th... more We describe a behavioural genetic extension of the classic multitrait‐multimethod study design that allows estimating genetic and environmental influences on method effects in twin studies (MTMM‐T). Genetic effects and effects of the environment shared by siblings are interpreted as indicators of convergent validity. In an application of the MTMM study design, we used self‐ and peer report data to examine the higher‐order structure of the NEO‐PI‐R. Structural equation modelling did not support a general factor of personality in multimethod data. The higher‐order factor Stability turns out to be, at most, a weak trait factor. Genetic effects on method factors indicate that especially self‐reports but also peer reports show convergent validity between twins but not between methods. Copyright © 2010 John Wiley & Sons, Ltd.
Journal of Personality and Social Psychology, 2010
People interested in the research are advised to contact the author for the final version of the ... more People interested in the research are advised to contact the author for the final version of the publication, or visit the DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:
International Journal of Obesity, 2021
Background/Objectives: Many personality traits correlate with BMI, but the existence and directio... more Background/Objectives: Many personality traits correlate with BMI, but the existence and direction of causal links between them are unclear. If personality influences BMI, knowing this causal direction could inform weight management strategies. Knowing that BMI instead influences personality would contribute to a better understanding of the mechanisms of personality development and the possible psychological effects of weight change. We tested the existence and direction of causal links between BMI and personality. Subjects/Methods: We employed two genetically informed methods. In Mendelian randomization, allele scores were calculated to summarize genetic propensity for the personality traits Neuroticism, Worry, and Depressive Affect and used to predict BMI in an independent sample (N=3 541). Similarly, an allele score for BMI was used to predict eating-specific and domain-general phenotypic personality scores (PPSs; aggregate scores of personality traits weighted by BMI). In a Direction of Causation analysis, twin data from five countries (N=5 424) were used to assess the fit of four alternative models: PPSs influencing BMI, BMI influencing PPSs, reciprocal causation, and no causation. Results: In Mendelian randomization, the allele score for BMI predicted domain-general (β=0.05; 95% CI 0.02, 0.08; P=.003) and eating-specific PPS (β=0.06; 95% CI 0.03, 0.09; P<.001). The allele score for Worry also predicted BMI (β=-0.05; 95% CI-0.08,-0.02; P<.001), while those for Neuroticism and Depressive Affect did not (P≥.459). In Direction of Causation, BMI similarly predicted domain-general (β=0.21; 95% CI 0.18, 0.24; P<.001) and eatingspecific personality traits (β=0.19; 95% CI 0.16, 0.22; P<.001), suggesting causality from BMI to personality traits. In exploratory analyses, links between BMI and domain-general personality 2 CAUSALITY BETWEEN BMI AND PERSONALITY traits appeared reciprocal for higher-weight individuals (BMI>~25). Conclusions: Although both genetic analyses suggested an influence of BMI on personality traits, it is not yet known if weight management interventions could influence personality. Personality traits may influence BMI in turn, but effects in this direction appeared weaker.
Based on a perspective on personality coherence as the extent to which personality-relevant chara... more Based on a perspective on personality coherence as the extent to which personality-relevant characteristics are differentiated and integrated within a person in his or her environment, we propose a synthesis that builds on and harmonizes existing and partly conflicting theories, methodological approaches, and empirical findings. This understanding of personality coherence needs clear definitions of person and environment characteristics. We define traits as characteristics of the person, adaptations as characteristics of the person-in-contexts, and states as characteristics of the person-in-situations. Thus, our synthesis involves concepts of environments and person-environment units. Next, we provide testable criteria to differentiate characteristics of persons from characteristics of person-environment units and to identify dispositional traits for a narrow-sense perspective on personality coherence. We raise awareness of the importance of fit between (profiles of) person and envi...
Journal of Personality and Social Psychology, 2018
Mõttus and colleagues (2017) reported evidence that the unique variance in specific personality c... more Mõttus and colleagues (2017) reported evidence that the unique variance in specific personality characteristics captured by single descriptive items often displayed trait-like properties of crossrater agreement, rank-order stability and heritability. They suggested that the personality hierarchy should be extended below facets to incorporate these specific characteristics, called personality nuances. The present study attempted to replicate these findings, employing data from 6,287 individuals from six countries (Australia, Canada, Czech Republic, Denmark, Japan, and United States). The same personality measure-240-item Revised NEO Personality Inventory-and statistical procedures were used. The present findings closely replicated the original results. When the original and current results were meta-analyzed, the unique variance of nearly all items (i.e., items' scores residualized for all broader personality traits) showed statistically significant crossrater agreement (median = .12) and rank-order stability over an average of 12 years (median = .24), and the unique variance of the majority of items had a significant heritable component (median =. 14). These three item properties were inter-correlated, suggesting that items systematically differed in the degree of reflecting valid unique variance. Also, associations of items' unique variance with age, gender, and Body Mass Index (BMI) replicated across samples and tracked with the original findings. Moreover, associations between item residuals and BMI obtained from one group of people allowed for a significant incremental prediction of BMI in an independent sample. Overall, these findings reinforce the hypotheses that nuances constitute the building blocks of the personality trait hierarchy, their properties are robust and they can be useful.
Personality Science, 2021
Personality traits continue to change throughout the lifespan. However, we still know little abou... more Personality traits continue to change throughout the lifespan. However, we still know little about when, why, and how personality traits change. In this paper, we review the current state of scientific evidence regarding the nature, sources, and processes of personality trait stability and change. We revisit past disputes over the relative importance of genetic and environmental influences, discuss studies on life events and personality trait development, and summarize theory and research on personality change processes. In doing so, we derive general principles of personality trait development, highlight limitations of past research, and present the broad outlines for future research on personality trait development, with a particular emphasis on relevant methodological issues and conceptual challenges.
Little research has examined age differences by using more than one source of information. We com... more Little research has examined age differences by using more than one source of information. We compared age differences in Five-Factor Model (FFM) facets and nuances in self-reports and ratings by knowledgeable informants using samples from three countries (Estonia, Germany, and the Czech Republic; N=5,624). We hypothesized that age differences would be larger in self- than informant-reports, because of greater social desirability in self-descriptions with advancing age. Indeed, we found that age differences were systematically smaller in informant-reports compared to self-reports; this trend was stronger for traits independently rated as socially desirable. As age differences may be best approximated by average trends of self- and informant-reports, we provide meta-analytic age trends for multi-rater composite scores of the FFM facets and nuances.
Current Directions in Psychological Science, 2020
There is now compelling evidence that people’s typical patterns of thinking, feeling, striving, a... more There is now compelling evidence that people’s typical patterns of thinking, feeling, striving, and behaving are both consistent and malleable. Therefore, researchers have begun to examine the distinct sources of personality stability and change. In this article, we discuss traditional classifications of sources, review key findings, and highlight limitations and open questions in research on personality stability and change. We conclude by describing an integrative model and by outlining important directions for future research.
Twin Research and Human Genetics, 2019
The Study of Personality Architecture and Dynamics (SPeADy) is a German research project that aim... more The Study of Personality Architecture and Dynamics (SPeADy) is a German research project that aims to investigate the sources of interindividual differences in intraindividual personality development. The main focus lies in the dynamic interplay between more stable core characteristics and more environmentally malleable surface characteristics, as well as between personality and life experiences over time. SPeADy includes a twin family study encompassing data from 1962 individuals (age: 14–94) of 682 families, including 570 complete twin pairs (plus 1 triplet set), 327 parents, 236 spouses and 145 children of twins. Data collection started in 2016 and data from the first wave are currently obtainable as open source. Available data comprise a broad range of personality variables, such as personality trait constructs, motives, interests, values, moral foundations, religiosity and self-related concepts. For the currently ongoing second wave of data collection, we added retrospective re...
Zeitschrift für Psychologie, 2019
This study was designed to provide detailed estimates of genetic and environmental sources of var... more This study was designed to provide detailed estimates of genetic and environmental sources of variance in the HEXACO personality traits. For this purpose, we analyzed data from a German extended twin family study including 573 pairs of twins as well as 208 mothers, 119 fathers, 228 spouses, and 143 offspring of twins. All participants provided self-reports on the HEXACO-60. Extended twin family analyses using structural equation modeling (SEM) yielded that additive and nonadditive genetic influences accounted for about 50% of the variance in personality traits. The remaining variance was primarily due to individual-specific environmental sources and random measurement error. Spousal similarity in Openness was attributable to assortative mating, whereas spousal similarity in Honesty-Humility was attributable to environmental circumstances, partly due to a shared social background and spouse-specific effects. Our analyses yielded specifics for different personality traits. However, transmission of trait similarity from one generation to the next was primarily genetic.
Personality traits are powerful predictors of outcomes in the domains of education, work, relatio... more Personality traits are powerful predictors of outcomes in the domains of education, work, relationships, health, and well-being. The recognized importance of personality traits has raised questions about their policy relevance – that is, their potential to inform policy actions designed to improve human welfare. Traditionally, the use of personality traits in applied settings has been predicated on their ability to predict valued outcomes, typically under the assumption that traits are functionally unchanging. This assumption, however, is both untrue and a limiting factor on using personality traits more widely in applied settings. In this paper, we present the case that traits can serve both as relatively stable predictors of success and actionable targets for policy changes and interventions. Though trait change will likely prove a more difficult target than typical targets in applied interventions, it also may be a more fruitful one given the variety of life domains affected by p...
European Journal of Personality, 2019
In two studies, we examined the genetic and environmental sources of the unfolding of personality... more In two studies, we examined the genetic and environmental sources of the unfolding of personality trait differences from childhood to emerging adulthood. Using self–reports from over 3000 representative German twin pairs of three birth cohorts, we could replicate previous findings on the primary role of genetic sources accounting for the unfolding of inter–individual differences in personality traits and stabilizing trait differences during adolescence. More specifically, the genetic variance increased between early (ages 10–12 years) and late (ages 16–18 years) adolescence and stabilized between late adolescence and young adulthood (ages 21–25 years). This trend could be confirmed in a second three–wave longitudinal study of adolescents’ personality self–reports and parent ratings from about 1400 Norwegian twin families (average ages between 15 and 20 years). Moreover, the longitudinal study provided evidence for increasing genetic differences being primarily due to accumulation of...
European Journal of Personality, 2018
This study investigated the association between different experiences of parenting and individual... more This study investigated the association between different experiences of parenting and individual right–wing authoritarianism (RWA) using twin family data comprising self– and informant reports. We applied a design that allowed us to examine whether the link between retrospective assessments of parenting and current RWA is effectively environmental or whether the association is attributable to genetic influences. We hypothesized that an authoritarian parenting style (low responsiveness and high demandingness) provided by the parents is associated with higher offspring's RWA, and that this association is similar for both twin siblings as a function of their genetic relatedness and shared familial experiences—that is, genotype–environment correlation. A sample of 875 twins as well as 319 mothers and 268 fathers completed a questionnaire on twins’ parental environment and their own authoritarian attitudes. Additionally, 1322 well–informed peers assessed twins’ RWA. Applying structu...
We adopted an expert-rating approach to generate a consensus Five Factor Model (FFM) profile of t... more We adopted an expert-rating approach to generate a consensus Five Factor Model (FFM) profile of the psychologically healthy person. In addition, we collected ratings from scholars with expertise in positive psychology and two samples of undergraduate psychology students to examine the agreement within and between different groups of raters. We then examined the reliability, heritability, rank-order stability, external validity, and normativeness of this expert-generated FFM profile of the healthy personality using data from seven different samples (N > 3,000). To do this, we computed a healthy FFM score for each participant by using intraclass q-correlation to match individual FFM profiles to the healthy personality prototype. Through these analyses, we aim to provide an initial but nonetheless comprehensive description of the nature and correlates of the healthy personality from a contemporary basic trait perspective.
Journal of Personality and Social Psychology, 2017
It has been argued that facets do not represent the bottom of the personality hierarchy-even more... more It has been argued that facets do not represent the bottom of the personality hierarchy-even more specific personality characteristics, nuances, could be useful for describing and understanding individuals and their differences. Combining two samples of German twins, we assessed the consensual validity (correlations across different observers), rank-order stability, and heritability of nuances. Personality nuances were operationalized as the 240 items of the Revised NEO Personality Inventory (NEO-PI-R). Their attributes were examined by analyzing item residuals, controlling for the variance of the facet the item had been assigned to and all other facets. Most nuances demonstrated significant (p < .0002) cross-method agreement and rank-order stability. A substantial proportion of them (48% in self-reports, 20% in informant ratings, and 50% in combined ratings) demonstrated a significant (p < .0002) component of additive genetic variance, whereas evidence for environmental influences shared by twins was modest. Applying a procedure to estimate stability and heritability of true scores of item residuals yielded estimates comparable to those of higher-order personality traits, with median estimates of rank-order stability and heritability being .77 and .52, respectively. Few nuances demonstrated robust associations with age and gender, but many showed incremental, conceptually meaningful, and replicable (across methods and/or samples) predictive validity for a range of interest domains and body mass index. We argue that these narrow personality characteristics constitute a valid level of the personality hierarchy. They may be especially useful for providing a deep and contextualized description of the individual, but also for the prediction of specific outcomes.
Journal of personality and social psychology, Jan 21, 2016
This multitrait multimethod twin study examined the structure and sources of individual differenc... more This multitrait multimethod twin study examined the structure and sources of individual differences in creativity. According to different theoretical and metrological perspectives, as well as suggestions based on previous research, we expected 2 aspects of individual differences, which can be described as perceived creativity and creative test performance. We hypothesized that perceived creativity, reflecting typical creative thinking and behavior, should be linked to specific personality traits, whereas test creativity, reflecting maximum task-related creative performance, should show specific associations with cognitive abilities. Moreover, we tested whether genetic variance in intelligence and personality traits account for the genetic component of creativity. Multiple-rater and multimethod data (self- and peer reports, observer ratings, and test scores) from 2 German twin studies-the Bielefeld Longitudinal Study of Adult Twins and the German Observational Study of Adult Twins-we...
European Journal of Personality, 2014
Most theories of personality development posit that changes in life circumstances (e.g. due to ma... more Most theories of personality development posit that changes in life circumstances (e.g. due to major life events) can lead to changes in personality, but few studies have examined the exact time course of these changes. In this article, we argue that time needs to be considered explicitly in theories and empirical studies on personality development. We discuss six notions on the role of time in personality development. First, people can differ before the event. Second, change can be non–linear and discontinuous. Third, change can be reversible. Fourth, change can occur before the event. Fifth, control groups are needed to disentangle age–related and event–related changes. Sixth, we need to move beyond examining single major life events and study the effects of non–normative events, non–events, multiple events, and minor events on personality. We conclude by summarizing the methodological and theoretical implications of these notions. Copyright © 2014 European Association of Personal...
European Journal of Personality, 2014
Increasing numbers of empirical studies provide compelling evidence that personality traits chang... more Increasing numbers of empirical studies provide compelling evidence that personality traits change across the entire lifespan. What initiates this continuing personality development and how does this development proceed? In this paper, we compare six theoretical perspectives that offer testable predictions about why personality develops the way it does and identify limitations and potentials of these perspectives by reviewing how they hold up against the empirical evidence. While all of these perspectives have received some empirical support, there is only little direct evidence for propositions put forward by the five–factor theory of personality and the theory of genotype → environment effects. In contrast, the neo–socioanalytic theory appears to offer a comprehensive framework that fits the empirical findings and allows the integration of other, more specialized, perspectives that focus on specific aspects of personality development like the role of time, systematic differences b...
Journal of Personality, 2010
This study considered the validity of the personality structure based on the Five-Factor Model us... more This study considered the validity of the personality structure based on the Five-Factor Model using both self-and peer reports on twins' NEO-PI-R facets. Separating common from specific genetic variance in self-and peer reports, this study examined genetic substance of different trait levels and rater-specific perspectives relating to personality judgments. Data of 919 twin pairs were analyzed using a multiple-rater twin model to disentangle genetic and environmental effects on domain-level trait, facetspecific trait, and rater-specific variance. About two thirds of both the domain-level trait variance and the facet-specific trait variance was attributable to genetic factors. This suggests that the more personality is measured accurately, the better these measures reflect the genetic structure. Specific variance in self-and peer reports also showed modest to substantial genetic influence. This may indicate not only genetically influenced self-rater biases but also substance components specific for self-and peer raters' perspectives on traits actually measured. Few behavioral genetic studies have focused on personality traits measured with two or more indicators like facet scales (Jang, Livesley, Angleitner, Riemann, & Vernon, 2002) or multiple raters such as self-and peer judges (Riemann, Angleitner, & Strelau, 1997). No study has combined the advantages of both so far, although a
European Journal of Personality, 2010
We describe a behavioural genetic extension of the classic multitrait‐multimethod study design th... more We describe a behavioural genetic extension of the classic multitrait‐multimethod study design that allows estimating genetic and environmental influences on method effects in twin studies (MTMM‐T). Genetic effects and effects of the environment shared by siblings are interpreted as indicators of convergent validity. In an application of the MTMM study design, we used self‐ and peer report data to examine the higher‐order structure of the NEO‐PI‐R. Structural equation modelling did not support a general factor of personality in multimethod data. The higher‐order factor Stability turns out to be, at most, a weak trait factor. Genetic effects on method factors indicate that especially self‐reports but also peer reports show convergent validity between twins but not between methods. Copyright © 2010 John Wiley & Sons, Ltd.
Journal of Personality and Social Psychology, 2010
People interested in the research are advised to contact the author for the final version of the ... more People interested in the research are advised to contact the author for the final version of the publication, or visit the DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:
International Journal of Obesity, 2021
Background/Objectives: Many personality traits correlate with BMI, but the existence and directio... more Background/Objectives: Many personality traits correlate with BMI, but the existence and direction of causal links between them are unclear. If personality influences BMI, knowing this causal direction could inform weight management strategies. Knowing that BMI instead influences personality would contribute to a better understanding of the mechanisms of personality development and the possible psychological effects of weight change. We tested the existence and direction of causal links between BMI and personality. Subjects/Methods: We employed two genetically informed methods. In Mendelian randomization, allele scores were calculated to summarize genetic propensity for the personality traits Neuroticism, Worry, and Depressive Affect and used to predict BMI in an independent sample (N=3 541). Similarly, an allele score for BMI was used to predict eating-specific and domain-general phenotypic personality scores (PPSs; aggregate scores of personality traits weighted by BMI). In a Direction of Causation analysis, twin data from five countries (N=5 424) were used to assess the fit of four alternative models: PPSs influencing BMI, BMI influencing PPSs, reciprocal causation, and no causation. Results: In Mendelian randomization, the allele score for BMI predicted domain-general (β=0.05; 95% CI 0.02, 0.08; P=.003) and eating-specific PPS (β=0.06; 95% CI 0.03, 0.09; P<.001). The allele score for Worry also predicted BMI (β=-0.05; 95% CI-0.08,-0.02; P<.001), while those for Neuroticism and Depressive Affect did not (P≥.459). In Direction of Causation, BMI similarly predicted domain-general (β=0.21; 95% CI 0.18, 0.24; P<.001) and eatingspecific personality traits (β=0.19; 95% CI 0.16, 0.22; P<.001), suggesting causality from BMI to personality traits. In exploratory analyses, links between BMI and domain-general personality 2 CAUSALITY BETWEEN BMI AND PERSONALITY traits appeared reciprocal for higher-weight individuals (BMI>~25). Conclusions: Although both genetic analyses suggested an influence of BMI on personality traits, it is not yet known if weight management interventions could influence personality. Personality traits may influence BMI in turn, but effects in this direction appeared weaker.
Based on a perspective on personality coherence as the extent to which personality-relevant chara... more Based on a perspective on personality coherence as the extent to which personality-relevant characteristics are differentiated and integrated within a person in his or her environment, we propose a synthesis that builds on and harmonizes existing and partly conflicting theories, methodological approaches, and empirical findings. This understanding of personality coherence needs clear definitions of person and environment characteristics. We define traits as characteristics of the person, adaptations as characteristics of the person-in-contexts, and states as characteristics of the person-in-situations. Thus, our synthesis involves concepts of environments and person-environment units. Next, we provide testable criteria to differentiate characteristics of persons from characteristics of person-environment units and to identify dispositional traits for a narrow-sense perspective on personality coherence. We raise awareness of the importance of fit between (profiles of) person and envi...
Journal of Personality and Social Psychology, 2018
Mõttus and colleagues (2017) reported evidence that the unique variance in specific personality c... more Mõttus and colleagues (2017) reported evidence that the unique variance in specific personality characteristics captured by single descriptive items often displayed trait-like properties of crossrater agreement, rank-order stability and heritability. They suggested that the personality hierarchy should be extended below facets to incorporate these specific characteristics, called personality nuances. The present study attempted to replicate these findings, employing data from 6,287 individuals from six countries (Australia, Canada, Czech Republic, Denmark, Japan, and United States). The same personality measure-240-item Revised NEO Personality Inventory-and statistical procedures were used. The present findings closely replicated the original results. When the original and current results were meta-analyzed, the unique variance of nearly all items (i.e., items' scores residualized for all broader personality traits) showed statistically significant crossrater agreement (median = .12) and rank-order stability over an average of 12 years (median = .24), and the unique variance of the majority of items had a significant heritable component (median =. 14). These three item properties were inter-correlated, suggesting that items systematically differed in the degree of reflecting valid unique variance. Also, associations of items' unique variance with age, gender, and Body Mass Index (BMI) replicated across samples and tracked with the original findings. Moreover, associations between item residuals and BMI obtained from one group of people allowed for a significant incremental prediction of BMI in an independent sample. Overall, these findings reinforce the hypotheses that nuances constitute the building blocks of the personality trait hierarchy, their properties are robust and they can be useful.